- play_arrow Common Configuration for All VPNs
- play_arrow VPNs Overview
- play_arrow Assigning Routing Instances to VPNs
- play_arrow Distributing Routes in VPNs
- play_arrow Distributing VPN Routes with Target Filtering
- Configuring BGP Route Target Filtering for VPNs
- Example: BGP Route Target Filtering for VPNs
- Example: Configuring BGP Route Target Filtering for VPNs
- Configuring Static Route Target Filtering for VPNs
- Understanding Proxy BGP Route Target Filtering for VPNs
- Example: Configuring Proxy BGP Route Target Filtering for VPNs
- Example: Configuring an Export Policy for BGP Route Target Filtering for VPNs
- Reducing Network Resource Use with Static Route Target Filtering for VPNs
- play_arrow Configuring Forwarding Options for VPNs
- play_arrow Configuring Graceful Restart for VPNs
- play_arrow Configuring Class of Service for VPNs
- play_arrow Pinging VPNs
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- play_arrow Common Configuration for Layer 2 VPNs and VPLS
- play_arrow Overview
- play_arrow Layer 2 VPNs Configuration Overview
- play_arrow Configuring Layer 2 Interfaces
- play_arrow Configuring Path Selection for Layer 2 VPNs and VPLS
- play_arrow Creating Backup Connections with Redundant Pseudowires
- play_arrow Configuring Class of Service for Layer 2 VPNs
- play_arrow Monitoring Layer 2 VPNs
- Configuring BFD for Layer 2 VPN and VPLS
- BFD Support for VCCV for Layer 2 VPNs, Layer 2 Circuits, and VPLS
- Configuring BFD for VCCV for Layer 2 VPNs, Layer 2 Circuits, and VPLS
- Connectivity Fault Management Support for EVPN and Layer 2 VPN Overview
- Configure a MEP to Generate and Respond to CFM Protocol Messages
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- play_arrow Configuring Group VPNs
- play_arrow Configuring Public Key Infrastructure
- play_arrow Configuring Digital Certificate Validation
- play_arrow Configuring a Device for Certificate Chains
- play_arrow Managing Certificate Revocation
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- play_arrow Configuring Layer 2 Circuits
- play_arrow Overview
- play_arrow Layer 2 Circuits Configuration Overview
- play_arrow Configuring Class of Service with Layer 2 Circuits
- play_arrow Configuring Pseudowire Redundancy for Layer 2 Circuits
- play_arrow Configuring Load Balancing for Layer 2 Circuits
- play_arrow Configuring Protection Features for Layer 2 Circuits
- Egress Protection LSPs for Layer 2 Circuits
- Configuring Egress Protection Service Mirroring for BGP Signaled Layer 2 Services
- Example: Configuring an Egress Protection LSP for a Layer 2 Circuit
- Example: Configuring Layer 2 Circuit Protect Interfaces
- Example: Configuring Layer 2 Circuit Switching Protection
- play_arrow Monitoring Layer 2 Circuits with BFD
- play_arrow Troubleshooting Layer 2 Circuits
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- play_arrow Configuring VPWS VPNs
- play_arrow Overview
- play_arrow Configuring VPWS VPNs
- Understanding FEC 129 BGP Autodiscovery for VPWS
- Example: Configuring FEC 129 BGP Autodiscovery for VPWS
- Example: Configuring MPLS Egress Protection Service Mirroring for BGP Signaled Layer 2 Services
- Understanding Multisegment Pseudowire for FEC 129
- Example: Configuring a Multisegment Pseudowire
- Configuring the FAT Flow Label for FEC 128 VPWS Pseudowires for Load-Balancing MPLS Traffic
- Configuring the FAT Flow Label for FEC 129 VPWS Pseudowires for Load-Balancing MPLS Traffic
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- play_arrow Connecting Layer 2 VPNs and Circuits to Other VPNs
- play_arrow Connecting Layer 2 VPNs to Other VPNs
- play_arrow Connecting Layer 2 Circuits to Other VPNs
- Using the Layer 2 Interworking Interface to Interconnect a Layer 2 Circuit to a Layer 2 VPN
- Applications for Interconnecting a Layer 2 Circuit with a Layer 2 Circuit
- Example: Interconnecting a Layer 2 Circuit with a Layer 2 VPN
- Example: Interconnecting a Layer 2 Circuit with a Layer 2 Circuit
- Applications for Interconnecting a Layer 2 Circuit with a Layer 3 VPN
- Example: Interconnecting a Layer 2 Circuit with a Layer 3 VPN
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- play_arrow Configuration Statements and Operational Commands
Control Word for BGP VPLS Overview
In a BGP VPLS network, transit routers must determine the payload for hash calculations for load balancing. While parsing an MPLS encapsulated packet for hashing, a transit router can incorrectly calculate an Ethernet payload as an IPv4 or IPv6 payload if the first nibble of the destination address MAC is 0x4 or 0x6, respectively. This false positive can cause out-of-order packet delivery over a pseudowire. This issue can be avoided by configuring a BGP VPLS edge (VE) router to request that other BGP VE routers insert a control word between the label stack and the MPLS payload.
By inserting a control word between the label stack and the Layer 2 header of a packet traversing a VPLS, the first nibble of the destination address MAC can be ensured to be 0, thus preventing the packet from being identified as an IPv4 or IPv6 packet. All VE routers should want incoming packets to contain control words.
BGP is used to negotiate the support for control words between
VE routers. You configure a VE router with the control-word parameter to indicate
the preference to receive packets with the control word. By setting
the control word, the VE router expects that all frames marked with
a label from the VPLS contain the control word. When remote VE routers
advertise their NLRI, if the control word is set on them as well,
both ends of the pseudowire have control-word support and the control
word is expected in packets arriving at the VE routers in both directions.
If a VE router doesn’t have the control word set, a VE router that does have a control word set will act as if the VE router without the control word can neither send nor accept BGP VPLS packets with a control word included.
